This invention relates to apparatus for continuously treating thermoplastic resin, more particularly acrylonitrile-butadiene-styrene (ABS) type resin consisting of a vinyl type molten polymer obtained by continuous lump polymerization or solution polymerization, a graft polymerized latex obtained by emulsion graft polymerizing a diene type rubbery polymer and a monomeric vinyl, or a mixed latex of the graft polymerized latex and rubbery polymerized latex for effecting precipitation and coagulation with lesser energy than prior art apparatus.
Among prior art methods of preparing ABS type resin are included:
1. a method of preparing the ABS type resin from a graft polymer obtained by emulsion polymerization or a vinyl type polymer obtained by suspension or lump polymerization;
2. a method of preparing the ABS type resin from a graft polymer obtained by emulsion polymerization and a vinyl type polymer obtained by emulsion polymerization;
3. a method of manufacturing the ABS type resin from a graft polymer obtained by emulsion polymerization and a vinyl type polymer obtained by emulsion or lump polymerization;
4. a method of preparing the ABS type resin in which a mixture of a graft polymer and a vinyl type polymer is synthesized in one step, that is one step emulsion polymerization, one step suspension polymerization, one step emulsion-suspension polymerization, or one step emulsion-lump polymerization; and
5. a method of preparing the ABS type resin from a graft polymer synthesized by the emulsion-suspension polymerization or the emulsion-lump polymerization, and the vinyl type polymer obtained by the method 1 or 2 described above.
However, the method 4 utilizing the single step polymerization is not suitable for a variety of products, while the method 3 is inferior to the methods 1 and 2 in the shock resistant property, especially in the low temperature shock resistant property. For this reason, the method 1 or 2, especially method 1 is used industrially.
Generally, the ABS type resin is prepared from graft polymerized latex obtained by subjecting to emulsion graft polymerization a diene type rubbery polymer and a vinyl monomer, and from a slurry of a suspension or lump polymerized vinyl type polymer, pellets of a vinyl type polymer, and a slurry of a suspension or lump shaped vinyl type polymer or pellets of a vinyl type polymer. More particularly the ABS type resin is manufactured by mixing, extruding and deairating a graft polymer isolated by precipitating, coagulating, dehydrating and drying a graft polymerized latex, vinyl type polymer beads obtained by dehydrating and drying a slurry of a vinyl type polymer obtained by suspension polymerization or pellets of a vinyl type polymer obtained by lump polymerization. Accordingly, the process of preparing the ABS type resin is extremely complicated and requires a variety of steps so that there are many disadvantages that drying cost as well as running cost are expensive, that the loss of the polymer during manufacturing is large and that a large labour is necessary. For these reasons, there have been proposed recovering techniques of latex from the methods 2 and 5 described above. However, the method 5 is not used commonly because of its technical difficulty. In method 2, the technique of recovering latex during the process of manufacturing the ABS type resin is only one type of recovering, so that there has been a request for developing technique that can be applied to many fields and is valuable for industrial use.